Who said "There's a sucker born every minute"?

The aphorism "There's a sucker born every minute" is often attributed to the legendary circus kingpin P.T. Barnum, but Barnum's biographer was unable to verify this. A more probably source is David Hannum, a Syracuse banker who in 1869 unwittingly purchased a phony stone colossus known as the Cardiff Giant. This strange story begins with a surreptitious cigar manufacturer named George Hull, who sculpted the giant from a ten-foot long block of gypsum, buried it in Cardiff, New York, "discovered" it, and put it on display (charging admission, of course). Crowds of spectators journeyed from all over the state of New York to see the "petrified American Goliath." Hull's hoax was hugely successful. He soon sold most of his interest in it to a group of businessmen headed by Hannum, who exhibited it for even higher admission fees. The Cardiff Giant was a national sensation and caught P.T. Barnum's entrepreneurial attentions; he wanted to display it himself. Unable to persuade Hannum to sell, Barnum created a replica, claimed it to be the original, and called Hannum's exhibit a hoax. (This last part, ironically, was the truth.) Referring to the duped patrons of Barnum's more successful exhibit, Hannum--not Barnum--is then alleged to have said, "There's a sucker born every minute." He then sued Barnum for defaming the original. Hannum lost when George Hull confessed all in court; finding that the giant was a phony, the judge ruled that Barnum could not be sued for calling it a forgery. Adding a strange twist to this tale of double deception, Hannum's quote was then misattributed to Barnum.